Forecasting applications, quantitative trading strategies, and financial research increasingly depend on prediction market intelligence. The largest prediction market ecosystem—PolyGram and the underlying Polymarket CLOB—makes comprehensive APIs available to developers seeking to construct applications atop this infrastructure.
Available APIs
Polymarket Gamma API (Market Data)
Market metadata, real-time pricing, and historical snapshots are delivered through the Gamma REST API:
- Base URL: https://gamma-api.polymarket.com
- Endpoints: /events, /markets, /positions, /activity
- Authentication: Public market data requires no authentication
- Rate limits: Unauthenticated requests are capped at approximately 100 per minute
Polymarket CLOB API (Order Book & Trading)
Order submission and real-time order book information are accessible via the CLOB API:
- Base URL: https://clob.polymarket.com
- Endpoints: /book, /trades, /orders, /prices/history
- WebSocket: wss://ws-subscriptions-clob.polymarket.com delivers live streaming updates
- Authentication: Order placement demands ECDSA-signed request validation
PolyGram API
Authenticated trading operations are supported through PolyGram's dedicated API layer:
- Comprehensive reference material available at PolyGram API Docs
- REST-based endpoints for order execution, account holdings, and market discovery
- API key-based authentication enables automated trading workflows
Common Developer Use Cases
- Algorithmic trading: Systematic position adjustments triggered by external data feeds
- Research dashboards: Tracking implied probabilities over time for sporting, political, or macroeconomic events
- Market aggregators: Cross-platform odds comparison and arbitrage identification
- Embedded widgets: Displaying current prediction market odds within editorial or informational websites
- Alert systems: Triggering notifications when market movements exceed specified boundaries
Getting Started: Fetch Market Data
This Python snippet demonstrates retrieving active events in real time:
import requests
response = requests.get(
"https://gamma-api.polymarket.com/events",
params={"limit": 10, "active": "true", "order": "volume24hr"}
)
events = response.json()
for event in events:
print(event["title"], event["volume"])FAQ
- Is the Polymarket API free to use?
- Market data through the Gamma API carries no cost, though rate limits apply. Submitting orders via the CLOB API requires a funded wallet and ECDSA-signed authentication; transaction costs follow standard blockchain fees but no platform surcharge is imposed.
- Can I paper trade with the API before risking real USDC?
- A sandbox environment is not available on Polymarket itself. Manifold Markets provides a testing API suitable for paper trading; once comfortable, migrate to live Polymarket or PolyGram CLOB operations with actual capital.
- Are there Python or JavaScript SDKs available?
- Community contributors have released unofficial libraries for both Python and JavaScript targeting Polymarket integration. Consult GitHub repositories including "polymarket-py" and "polymarket-js" to locate actively maintained implementations.